Microcalorimetric investigation of amylopectin branching and the content of amylose in potato starches

Hydroxyethylated starches are of particular interest for applications in infusion therapy because of their high volemic effect. The duration of this effect depends on the circulation time of the drug in the blood, i.e., the volume of circulating blood increases with an increase in the concentration, molecular weight and degree of polymer substitution. It is known that hydroxyethylated starches have a wide range of molecular weight and degree of substitution. This allows their solutions to circulate for a long time (up to 10 hours) in the bloodstream without leakage of the active substance into the interstitium of vital organs. The dependence of the melting point of the crystalline starch lamella on the number of glucose residues can be described using the modified Fox - Loshaek ratio, which takes into account the degree of branching of amylopectin molecules and the content of amylose in starch. We proposed an analytical expression for the evaluation of the degree of branching of amylopectin from potato starch based on microcalorimetric data. The proposed methodology allows the genotypes of potatoes with the highest degree of amylopectin branching and a minimum quantity of amylose in starch to be selected. Starches of such potato varieties can be used in the blood plasma substitutes production - hydroxyethylated starches that have good pharmacodynamic properties. Within the developed approach, it is possible to determine the effect of the degree of substitution on the thermodynamic properties of the studied starches through a change in the melting temperature of the lamella, T_m, hence estimating the main pharmacodynamic parameters of substituted starches.

1. Khalikova E.Yu. Safety and efficacy of HES in infusion therapy programs. Trudnyi patsient. 2012;10(5):22-29. (In Russian)

2. Pustovoit VL, Dobrokhotov DA, Nesterova NV. Hydroxyethyl starch as an alternative colloidal blood substitute of the coarse nature of modern clinical practice. In: Open Innovation: Trudy VIII Mezhdunarodnoi nauchno-prakticheskoi konferentsii = Open Innovation: Proceedings of VIII International Scientific and Practical Conference. Penza, 23 April 2019. Penza: Nauka i Prosveshchenie, 2019, pp. 272-276. (In Russian)

3. Giordano G, Pugliese F, Bilotta F. Hydroxyethyl starch and fluid challenge. European Journal of Anaesthesiology. 2020;37(7):611-621. https://doi.org/10.1097/EJA.0000000000001147

4. Traven VF, Panov AV, Dolotov SM, Strelnikova TA, Suslov VV, Gladyrev VV. Comparative analysis of potato and corn starch hydroxyethylation products by gas-liquid chromatography and 13C NMR spectroscopy. Khimija rastitel'nogo syrja = Chemistry of plant raw material. 2009;3:57-61. (In Russian)

5. Sukhotin SK. Possibilities of plasma-substituting solutions of hydroxyethylated starch (HES) in resuscitation and surgery. Refortan®, Refortan® plus, Stabizol®. Dal'nevostochnyi meditsinskii zhurnal. 2001;S4:68-72. (In Russian)

6. Omar MN, Shouk TA, Khaleq MA. Activity of blood coagulation and fibrinolysis during and after hydroxyethyl starch (HES) colloidal volume replacement. Clinical Biochemistry. 1999;32(4):269-274. https://doi.org/10.1016/s0009-9120(99)00014-4

7. Wasserman LA, Krivandin AV, Filatova AG, Vasil'ev VG, Kolachevskaya OO, Tarasov VF, et al. Structural and thermodynamic characteristics of potato starches depending on the plant genotype and their cultivation conditions. Chimicheskaya fizika = Russian Journal of Physical Chemistry B: Focus on Physics. 2020;39(6):63-70. (In Russian) https://doi.org/10.31857/S0207401X2006014X

8. Fox TG, Flory PJ. Second-Order Transition Temperatures and Related Properties of Polystyrene. I. Influence of Molecular Weight. Journal of Applied Physics. 1950;21(6):581-591. https://doi.org/10.1063/1.1699711

9. Fox TG, Loshaek S. Influence of molecular weight and degree of crosslinking on the specific volume and glass temperature of polymers. Journal of Polymer Science. 1955;15(80):371-390. https://doi.org/10.1002/pol.1955.120158006

10. Askadskii AA. Computational materials science of polymers. United Kingdom: Cambridge International Science Publishing; 2003. 696 p.

11. Sommermeyer K, Cech F, Schossow R. Differences in chemical structures between waxy maize- and potato starch-based hydroxyethyl starch volume therapeutics. Transfusion Alternatives in Transfusion Medicine. 2007;9(3):127-133. https://doi.org/10.1111/j.1778-428X.2007.00071.x

12. Askadskii AA, Slonimskii GL, Matveev YuI, Korshak VV. Macromolecule packaging and glass transition temperature of polymers. Vysokomolekulyarnye soedineniya. Seriya A = Polymer Science. Series A. 1976;18(9):2067-2074. (In Russian)

13. Matveev YuI, Plashchina IG. A dynamic model of the effect of methyl resorcinol on the enzymatic activity of lysozyme. Polymer Science. Series A. 2011;53(5):390-396. https://doi.org/10.1134/S0965545X11050063

14. Matveev YuI, Askadskii AA. Calculation of the temperature of polymer transition into the viscous flow state. Vysokomolekulyarnye soedineniya. Seriya A = Polymer Science. Series A. 1993;35(1):63-67. (In Russian)

15. Askadskii AA, Kovriga OV. Effect of branching on the physical characteristics of polymers. Polymer Science U.S.S.R. 1991;33(9):1891-1831. https://doi.org/10.1016/0032-3950(91)90019-M

16. Papakhin AA, Lukin ND, Ananskikh VV, Borodina ZM. Modern trends in starch hydrolysis technology. Dostizheniya nauki i tekhniki APK. 2020;34(12):84-89. (In Russian) https://doi.org/10.24411/0235-2451-2020-11214